How does the Brake Booster Solenoid work?

[eacmen]

I will give it a shot, but I think I have tried that. Valve clicks with key in start position when I unplug it and plug back in, so I assume functional.
After clearing up vacuum leak at the air rail and almost completely at the MAP sensor (still a small leak...) I still have idle issues, engine is running rough after cold start cycle, it gets worse when I hit the brake pedal.

sounds like it might be a vac leak from the booster or failed check valve

pull the valve from the booster and cap the valve to see if your engine idle improves.

what are the fuel trims?

do you have a smoke tester?

[fattycharged]

sounds like it might be a vac leak from the booster or failed check valve

pull the valve from the booster and cap the valve to see if your engine idle improves.

what are the fuel trims?

do you have a smoke tester?

unplugged booster, only slight change.
fuel trims I don't know, my Foxwell decided it won't connect in OBD today, yesterday no issue.

yes, used smoke tester to find air rail leaks. all good last check

also throwing both pre cat faults it seems.

going to have to put this to rest till next week unfortunately, leaving town tomorrow evening, but looks like I have some work to do before this thing goes on it's first born-again journey


Sent from my iPhone using Tapatalk

[eacmen]

unplugged booster, only slight change.
fuel trims I don't know, my Foxwell decided it won't connect in OBD today, yesterday no issue.

yes, used smoke tester to find air rail leaks. all good last check

also throwing both pre cat faults it seems.

going to have to put this to rest till next week unfortunately, leaving town tomorrow evening, but looks like I have some work to do before this thing goes on it's first born-again journey


Sent from my iPhone using Tapatalk

Did you recently install a tune? Any work in the ECU box?

The fact that you can't connect with the scan tool is suspect on its own and may indicate an issue on the ECU side…

[fattycharged]

Did you recently install a tune? Any work in the ECU box?

The fact that you can't connect with the scan tool is suspect on its own and may indicate an issue on the ECU side…

Agreed. No new tune. Yes, I've been in there the past few days, I decided to change out the MAP sensor and wiring, which was resolved for now.

For clarity, I can connect to the tool to pull codes through BMW function, just not through the OBDII function, which I had seen before, its intermittent and I did not have a trickle running on the batt.

I'll try to connect next week through my laptop, need to install parallels, pull some logs


Sent from my iPhone using Tapatalk

[bigjae46]

Agreed. No new tune. Yes, I've been in there the past few days, I decided to change out the MAP sensor and wiring, which was resolved for now.

For clarity, I can connect to the tool to pull codes through BMW function, just not through the OBDII function, which I had seen before, its intermittent and I did not have a trickle running on the batt.

I'll try to connect next week through my laptop, need to install parallels, pull some logs


Sent from my iPhone using Tapatalk

Long shot...something to consider as a possibility. Could be an ECU issue. Randy at Epic would be my go to if you go down that road. Not sure if you're there yet...I need to see more desperation in your posts before I'd recommend trying that...lol

[fattycharged]

Long shot...something to consider as a possibility. Could be an ECU issue. Randy at Epic would be my go to if you go down that road. Not sure if you're there yet...I need to see more desperation in your posts before I'd recommend trying that...lol

Not quite there yet…we'll see next week


Sent from my iPhone using Tapatalk